Are there any software engineers working at trading or financial firms here?

I've always been fascinated by finance and trading, and I’m curious about the opportunities available in this space for engineers. Would love to one day end up in the field. I’m not talking about banks or fintech companies like Stripe or Revolut—I mean firms like HRT, Virtu, SIG, Millennium, MayStreet, and similar companies.

I know the above firms and many others have offices here. However, due to the nature of these roles, there isn't a lot of accessible information about them.

For those of you who work in this area in Ireland, I’d love to hear about how you ended working up in a trading or financial firm? Did any of you transition from more traditional development roles (e.g. working at tech companies) into the finance world?